Namura .040 Over Bore Top End Rebuild Kit for Honda TRX400EX & TRX400X 86mm

.040 Over Bore Top End Rebuild Kit for Namura

This top end rebuild kit provides a .040 over bore piston kit sized at 86mm for Honda TRX400EX and TRX400X ATVs, including all necessary components for a complete top end rebuild.

Overview

The .040 over bore top end rebuild kit for Namura is designed for Honda TRX400EX and TRX400X models, offering a reliable solution to restore lost compression and power. This kit includes a high-performance piston, rings, wrist pin, and gaskets, ensuring a thorough refresh of the engine's top end. It is ideal for dirt and sport ATV enthusiasts seeking to revive their machine's performance.

Built For Performance

• Precision-machined piston with .040 over bore sizing
• High-quality ring set for optimal seal and compression
• Includes complete gasket set for hassle-free installation
• Designed for Honda TRX400EX and TRX400X engines
• Durable construction to withstand high RPM operation

Fits These Machines

• for Honda TRX400EX
• for Honda TRX400X

On-The-Job Use

• Restoring top end performance on worn ATV engines
• Rebuilding engines after bore damage or wear
• Preparing race or trail ATVs for competitive use
• Replacing original piston during scheduled maintenance

Specs At A Glance

Good To Know

Q: Does this kit include a piston pin and clips? A: Yes, the kit typically includes the wrist pin and circlips for complete installation.

Q: Do I need to rejet the carburetor after installing an overbore piston? A: It is recommended to check and adjust jetting due to increased displacement, but many riders find the stock jetting adequate for mild overbores.

Slight variation in finish or dimensions may occur between production runs, and fit can depend on serial number, so confirm compatibility before ordering.